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Starting with a realistic quark model of nucleon structure, in which quarks are strongly correlated with one another within the nucleon, the light nuclei 2H, 3H, 3He, and 4He can be constructed by assuming similar correlations with the quarks in neighboring nucleons. Importance of color loops created owing to the closure of quark ends of adjacent nucleons is emphasized. Applying the model to larger nucleon systems reveals the emergence of symmetries at the nuclear level that are isomorphic with those known from the independent-particle (shell) model.

The cross sections for (d, xn), (d, pxn), (p, xn), and (p, pxn) reactions on enriched tin isotopes are obtained at a projectile energy of 3.65 GeV per nucleon. The yields in the energy range 0.66–8.1 GeV are analyzed with resort to experimental data obtained previously. Experimental data are compared with the results of theoretical calculations performed within the cascade-evaporation model. The dependence of the yields on the number of emitted neutrons, the projectile type, and the isotopic composition of a target is investigated. The cross sections for the (p, xpyn) reactions on a 120Sn target are presented at a primary-proton energy of 0.66 GeV.

In proton-nucleus reactions, the ratios of the cross sections for 18 isomeric pairs were measured by the induced-activity method as functions of the initial-proton energy and of the number of emitted nucleons. The isotopic effect and the cross sections for charge-exchange reactions are discussed. The experimental values of the cross sections for disintegration reactions like (p, xpyn) are compared with the theoretical values calculated on the basis of the cascade-evaporation model.